1. Field
At least one feature relates to acquisition of communication systems, and, more particularly, to a method for assisting a communication device to improve wireless network acquisition time by obtaining information from other communication devices already in the network.
2. Background
In wireless communication networks, an access terminal or mobile device/station typically scans a defined frequency spectrum to identify one or more access nodes (e.g., cells, base stations, Node Bs, Access Node, etc.) through which it may obtain wireless communication service. This is often referred to as system acquisition and typically happens when the mobile station (MS) is powered On after being off for some time or when the mobile station recovers from lack of coverage or switches between two different networks (e.g., 2G and 3G networks). In these cases, the mobile station searches through a list of carrier frequency candidates. For each frequency, the mobile station may attempt to detect a preamble or acquire a scrambling code and phase of the strongest access node detected or found. The length of the frequency list depends on the actual scenario, e.g. if the mobile station has been moved outside it home coverage area (e.g., service region, state city, country, etc.) while it was powered off, then the frequency list can be quite long. Most often, the correct carrier frequency is not known and the frequency scanning process involves a coarse frequency scan (e.g., where a frequency band may be identified) followed by fine frequency scan (e.g., where particular channels within the frequency band may be scanned). Cell acquisition (e.g., access node acquisition) may then be done on each channel where energy is found during the fine frequency scan. During the cell acquisition, the mobile station searches for service both in frequency and code space which is typically an undesirably large number of hypotheses or combinations to search. Once an appropriate access node is selected, the mobile station is ready to communicate signaling messages to establish a data and/or voice session via the selected access node.
Due to the scanning performed by the mobile station to identify access nodes and acquire a scrambling code and phase, the acquisition process may take a noticeably long time. Consequently, a way is needed to expedite and/or improve the acquisition process service may be acquired more quickly by a mobile station.